In several commonly owned U.S. patents, including Nos. 3,974,066, 4,138,170 and 4,153,309, a cage with pockets accommodating a set of such rotary bodies is disclosed as having a lip remote from these pockets which is snap-fitted into an annular groove of one of the bearing rings in order to keep these bodies in line with the track surfaces of the rings.
The splitting of one or both rings, e.g. as taught in commonly owned U.S. Pat. No. 4,089,570, simplifies the assembly of the rings, rotary bodies and associated cage or cages into a unit as well as the mounting of that unit between two coaxial members, such as a shaft and a housing, which are to be supported for relative rotation. Problems may arise, however, during storage of such units in disassembled form since their components may be accidentally interchanged and may then not properly interfit with the precision required for a smooth-running journal bearing. Moreover, the demounting of the unit is difficult when only one ring (e.g. the outer one, as is often the case) is readily accessible, especially when the track surfaces of that ring are bounded only by oppositely facing inner shoulders thereof but are outwardly shoulderless in order to simplify the task of machining the track boundaries. With oblique seat axes in an "O" or "X" mounting (see the aforementioned U.S. Pat. No. 3,975,066) the rotary bodies will be in contact during operation with only the internal shoulders of one ring and the external shoulders of the other ring; still, the provision of additional track boundaries without precision machining for the sake of holding the unit together would be detrimental since, on demounting, the bodies would come in contact with these rough boundaries and could be damaged thereby.
It has already been proposed (see French Pat. No. 2,138,283) to provide two sets of bearing balls with a common cage having two crenellated surfaces which define respective arrays of oppositely facing pockets for these bodies, the arrays being relatively staggered in peripheral direction for the purpose of saving space. The pockets form seats which are spherically curved over more than 180.degree. whereby the balls are resiliently retained therein. Even with this arrangement, however, it is necessary to provide the axially split inner ring with internal and external track boundaries constituted by concave shoulders of appreciable height.
According to another earlier proposal (see German utility model No. 1,768,081) the two halves of the axially divided inner bearing ring are held together by a split ring of C-profile engaging in respective annular grooves of these halves between two sets of balls. When the unit is to be disassembled for any reason, e.g. for the replacement of a worn ball, the split ring must be removed by a special tool inasmuch as the balls are confined by external shoulders of the inner ring halves and internal and external shoulders of the unitary outer ring.